I don’t see how this would be classed as an advertisement. I have no affiliation with McDonald’s and at the end of the day this is a meme that will likely have no effect on their brand image given the strength of their branding already and the relatively miniscule reach of this post. I think it would be a bit overzealous to remove this on the grounds of advertising.
I respect that however I am not sure if it is realistic to be able to completely eradicate branding from a platform such as this one, especially in a meme community. I appreciate your point of view and where you’re coming from, but the problem that you’re describing is occurring at a much higher level in society and I’m not sure that it is something that can be tackled here without upsetting people.